Linux 4.15 compat: timer updates

Use timer_setup() macro and new timeout function definition.

Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Tony Hutter <[email protected]>
Closes #670
Closes #671 

2 files changed, 59 insertions, 2 deletions

diff --git a/config/spl-build.m4 b/config/spl-build.m4
index 7b66f2c86..926abd5c8 100644
--- a/config/spl-build.m4
+++ b/config/spl-build.m4
@@ -54,6 +54,7 @@ AC_DEFUN([SPL_AC_CONFIG_KERNEL], [
 	SPL_AC_WAIT_QUEUE_HEAD_ENTRY
 	SPL_AC_KERNEL_WRITE
 	SPL_AC_KERNEL_READ
+	SPL_AC_KERNEL_TIMER_FUNCTION_TIMER_LIST
 ])
 
 AC_DEFUN([SPL_AC_MODULE_SYMVERS], [
@@ -1654,3 +1655,36 @@ AC_DEFUN([SPL_AC_KERNEL_READ], [
 	])
 	EXTRA_KCFLAGS="$tmp_flags"
 ])
+
+dnl #
+dnl # 4.15 API change
+dnl # https://lkml.org/lkml/2017/11/25/90
+dnl # Check if timer_list.func get passed a timer_list or an unsigned long
+dnl # (older kernels).  Also sanity check the from_timer() and timer_setup()
+dnl # macros are available as well, since they will be used in the same newer
+dnl # kernels that support the new timer_list.func signature.
+dnl #
+AC_DEFUN([SPL_AC_KERNEL_TIMER_FUNCTION_TIMER_LIST], [
+	AC_MSG_CHECKING([whether timer_list.function gets a timer_list])
+	tmp_flags="$EXTRA_KCFLAGS"
+	EXTRA_KCFLAGS="-Werror"
+	SPL_LINUX_TRY_COMPILE([
+		#include <linux/timer.h>
+		void task_expire(struct timer_list *tl) {}
+	],[
+		#ifndef from_timer
+		#error "No from_timer() macro"
+		#endif
+
+		struct timer_list timer;
+		timer.function = task_expire;
+		timer_setup(&timer, NULL, 0);
+	],[
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_KERNEL_TIMER_FUNCTION_TIMER_LIST, 1,
+		    [timer_list.function gets a timer_list])
+	],[
+		AC_MSG_RESULT(no)
+	])
+	EXTRA_KCFLAGS="$tmp_flags"
+])
diff --git a/module/spl/spl-taskq.c b/module/spl/spl-taskq.c
index 50f6f520f..ae26bdb2e 100644
--- a/module/spl/spl-taskq.c
+++ b/module/spl/spl-taskq.c
@@ -206,9 +206,9 @@ task_done(taskq_t *tq, taskq_ent_t *t)
  * add it to the priority list in order for immediate processing.
  */
 static void
-task_expire(unsigned long data)
+task_expire_impl(taskq_ent_t *t)
 {
-	taskq_ent_t *w, *t = (taskq_ent_t *)data;
+	taskq_ent_t *w;
 	taskq_t *tq = t->tqent_taskq;
 	struct list_head *l;
 	unsigned long flags;
@@ -242,6 +242,21 @@ task_expire(unsigned long data)
 	wake_up(&tq->tq_work_waitq);
 }
 
+#ifdef HAVE_KERNEL_TIMER_FUNCTION_TIMER_LIST
+static void
+task_expire(struct timer_list *tl)
+{
+	taskq_ent_t *t = from_timer(t, tl, tqent_timer);
+	task_expire_impl(t);
+}
+#else
+static void
+task_expire(unsigned long data)
+{
+	task_expire_impl((taskq_ent_t *)data);
+}
+#endif
+
 /*
  * Returns the lowest incomplete taskqid_t.  The taskqid_t may
  * be queued on the pending list, on the priority list, on the
@@ -581,7 +596,9 @@ taskq_dispatch(taskq_t *tq, task_func_t func, void *arg, uint_t flags)
 	t->tqent_func = func;
 	t->tqent_arg = arg;
 	t->tqent_taskq = tq;
+#ifndef HAVE_KERNEL_TIMER_FUNCTION_TIMER_LIST
 	t->tqent_timer.data = 0;
+#endif
 	t->tqent_timer.function = NULL;
 	t->tqent_timer.expires = 0;
 	t->tqent_birth = jiffies;
@@ -631,7 +648,9 @@ taskq_dispatch_delay(taskq_t *tq, task_func_t func, void *arg,
 	t->tqent_func = func;
 	t->tqent_arg = arg;
 	t->tqent_taskq = tq;
+#ifndef HAVE_KERNEL_TIMER_FUNCTION_TIMER_LIST
 	t->tqent_timer.data = (unsigned long)t;
+#endif
 	t->tqent_timer.function = task_expire;
 	t->tqent_timer.expires = (unsigned long)expire_time;
 	add_timer(&t->tqent_timer);
@@ -723,7 +742,11 @@ taskq_init_ent(taskq_ent_t *t)
 {
 	spin_lock_init(&t->tqent_lock);
 	init_waitqueue_head(&t->tqent_waitq);
+#ifdef HAVE_KERNEL_TIMER_FUNCTION_TIMER_LIST
+	timer_setup(&t->tqent_timer, NULL, 0);
+#else
 	init_timer(&t->tqent_timer);
+#endif
 	INIT_LIST_HEAD(&t->tqent_list);
 	t->tqent_id = 0;
 	t->tqent_func = NULL;